OPTIMIZATION OF OSMOTIC DEHYDRATION OF CAULIFLOWER

Osmotic dehydration of cauliflower as influenced by temperature (40-90 C), salt concentration (5-25%), ratio of brine to material (2-4, w/w) and time (5-180 min), was studied through central composite roratable design (CCRD) under response surface methodology. Responses of weight loss (%) and salt pickup (%) were fitted to polynomials of second degree requiring 6 and 7 terms, respectively, with multiple correlation coefficients of 0.97 and 0.98. The fitted functions were optimized for maximum weight loss and with 4% salt pickup using a flexible polyhedron search method. Our of four such optimum sets one was selected based on the actual weight losses in the verification experiments with larger batch sizes, color and appearance, texture and rehydration properties of the dried materials. The optimum conditions required the material to be processed at 80C for 5 min in 2 times (w/w) of 12% brine. The selected optimum as well as two other optimum sets also inactivated polyphenol oxidase which causes enzymatic browning.